The importance of keeping standards relevant and up to date
It is indeed important to periodically revise and update acoustic norms. This can take into account for developments like; advancements in technology, changing usage patterns, and evolving needs in indoor environments. As technology and audio-visual systems continue to advance, how we use and experience indoor spaces can significantly change. Acoustic norms need to adapt accordingly. Here are a few reasons why revising acoustic norms is beneficial:
a] Technological Advancements: Factoring in new audio and video technologies, such as; advanced sound systems, immersive audio, virtual reality, and teleconferencing systems. These can all impact the acoustic requirements of indoor spaces. Revising norms allows for the inclusion of guidelines that address the integration and optimal use of these technologies while ensuring good acoustic performance.
b]Evolving Usage Patterns: The way we utilize indoor spaces has evolved over time. For example, open-plan offices, flexible workspaces, coworking spaces, and multi-purpose venues have become more prevalent. Revising acoustic norms enables the development of guidelines. Enabling consideration of specific acoustic needs of these contemporary spaces and promote comfort, productivity, and efficient communication.
c] Changing Building Materials and Designs: Advances in building materials, construction techniques, and architectural designs may influence the acoustic characteristics of indoor environments. Taking into account the acoustic properties of new materials and the impact of innovative design is more than desirable.
d]Improved Understanding of Human Perception: Ongoing research in psychoacoustics and human perception of sound can provide valuable insights into how acoustic environments affect people. Considering the relationship between sound and human experience in the norms can enhance comfort, well-being, and cognitive performance.
e]Sustainability and Energy Efficiency: Acoustic norms can also be revised to address sustainability and energy efficiency concerns. This includes guidelines for the use of eco-friendly sound-absorbing materials and recommendations for energy-efficient acoustic design practices.
The key aspects being revised in the Czech Acoustic Standard
After 16 years there is an initiative ongoing to revise the standard CSN 73 0527 Acoustics – Acoustical design of rooms – Rooms for cultural uses – Rooms in schools – Rooms for public purposes. There have been several main reasons for it:
a) missing acoustic parameters and recommendations for a number of spaces (within offices, hospitals)
b) need to adapt RT values for multipurpose halls in accordance with the currently used technologies and trends in the usage of these spaces
c) discrepancies for reverberation time requirements for small-volume classrooms and auditoriums
d) broadband suspended ceiling stated for certain spaces without consideration of alternative solutions
Insights from the Czech Acoustic Standard working group
The revision of the standard has been entrusted to a specially created working group headed by the authorized acoustician Tomas Hradek. Iveta Kralova, Local Concept Developer with Saint-Gobain Ecophon, interviewed Tomas Hradek:
Could you mention the team working on this revision? Are all of you acousticians?
For the processing of the standard, a four-member working group consisting of four acousticians with extensive experience, particularly in the field of room acoustics, was established. The aim of such a team composition was to incorporate as many practical experiences as possible into the standard.
There is a newly used parameter Equivalent Absorption Area (A) for some spaces, resp. A in correlation with volume (V). What was the reason for this?
The goal was to establish a universal regulation for spaces requiring noise reduction, which would replace the requirement for the application of a broadband acoustic ceiling that did not consider the use of either standalone acoustic elements or wall absorbers, thus being significantly limiting in practice. The inspiration for using the ratio of equivalent absorption area A to volume V as a suitable target parameter was the German standard DIN.
Did you manage to include spaces where you were missing acoustic requirements? We tried not to overlook any spaces. A standard can never cover all eventualities, but the goal was to classify everything that is frequently encountered in practice. I would mention spaces such as hospital rooms, meeting rooms, restaurants, or receptions, for which no regulations existed, and everything was addressed by referring to various requirement equivalents.
Does it mean that all the recommended values (RT or A/V) are mandatory and must be fulfilled by approval of a premise?
The standard is legally binding according to Decree No. 343/2009 Coll., solely for school and educational spaces for children and young people. Therefore, it is mandatory for schools and all other spaces where education takes place, including, for example, sports halls. The remaining parts of the standard have a recommendatory nature.
Is speech intelligibility also taken into account for specific rooms – such as foreign language classrooms?
Speech intelligibility is mentioned multiple times in the standard (e.g. in relation to electro-acoustic sound reinforcement), but it is not specified as a target parameter. The reason is the lack of a standardized design method with a guarantee of achieving calculated values. This would create an issue regarding responsibility for the accuracy of the design. Therefore, we have focused on the reverberation time requirement, for which achieving target values is feasible. When general design principles are followed, the values of reverberation time and speech intelligibility are, in most standard spaces, highly correlated and in good agreement.
When can we expect the revision to enter into force?
Currently, it is anticipated that the standard will come into effect in September 2023.
Tomas graduated at the Faculty of Electrical Engineering at CTU in Prague and is an authorized ČKAIT technician in the field of building environment technology that includes acoustic studies. He is one of the founding owners of AVETON company.
Acoustician Tomas Hradek, a founding owner of AVETON company
Compliance with acoustic norms helps architects, engineers, and designers create indoor environments that promote optimal acoustic conditions. This is controlled by Hygiene authorities, specific bodies established by The Czech Ministry of Health. The new wording of the norm will be valid for newly built, reconstructed and adapted buildings.
